TOTOLINK A3700R cstecgi.cgi setL2tpServerCfg access control

published 2025-04-16 18 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-11154

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits: 0; none known

A vulnerability was found in TOTOLINK A3700R 9.1.2u.5822_B20200513. It has been rated as critical. Affected by this issue is the function setL2tpServerCfg of the file /cgi-bin/cstecgi.cgi. The manipulation leads to improper access controls. The attack may be launched remotely. The exploit has been disclosed to the public and may be used.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: yes
Technical impact: partial
Assessed: 18 mo ago (2025-04-16)

Exploit prediction

0.62% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

lavender-bicycle-a5a.notion.site https://lavender-bicycle-a5a.notion.site/TOTOLINK-A3700R-setL2tpServerCfg-1cb53a41781f80319d38dc5a8e9174ae?pvs=4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA	3.0	5.3	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:P/A:N
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected products

TOTOLINK A3700R

Classification

Weakness

CWE-284 Improper Access Control
CWE-266 Incorrect Privilege Assignment

References

lavender-bicycle-a5a.notion.site /TOTOLINK-A3700R-setL2tpServerCfg-1cb53a41781f80319d38dc5a8e9174ae?pvs=4
exploit, third-party-advisory
vuldb.com /?id.304964
vdb-entry, technical-description, third-party-advisory
vuldb.com /?ctiid.304964
signature, permissions-required
vuldb.com /?submit.551304
third-party-advisory, vdb-entry
totolink.net /
product

Sources

CVE List CVE-2025-3675
NVD CVE-2025-3675

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary